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October 28, 1997

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Saccharin Still Poses Cancer Risk,
Scientists Tell Federal Agency

Saying that numerous studies indicate that saccharin may cause cancer, a group of scientists is
urging the government to keep that artificial sweetener on its list of cancer-causing chemicals.
Their statement opposes efforts by the diet-food industry to remove the cancer label from
saccharin and the foods in which it is used.

In a joint letter, the scientists told the National Toxicology Program, a division of the National
Institute of Environmental Health Sciences, that declaring saccharin safe would "result in greater
exposure to this probable carcinogen in tens of millions of people, including children (indeed,
fetuses). If saccharin is even a weak carcinogen, this unnecessary additive would pose an
intolerable risk to the public."

The staff of the National Toxicology Program, in response to a petition from the diet-food
industry's Calorie Control Council, has recommended to the NTP's Board of Scientific Counselors
that saccharin be "delisted." The board, a committee of outside scientists, will vote on the matter
on October 31 at a meeting in Research Triangle Park, North Carolina.

"With numerous studies suggesting that saccharin may cause cancer in humans," said
epidemiologist Richard Clapp, who co-signed the letter to the NTP, "we should be extremely
cautious, because saccharin is consumed by a huge number of people." Dr. Clapp is an associate
professor in Boston University's Department of Environmental Health.

Samuel Epstein, M.D., another co-signer, said, "In light of the many animal and human studies
clearly demonstrating that saccharin is carcinogenic, it is astonishing that the NTP is even
considering delisting saccharin." Dr. Epstein is a professor of environmental medicine at the
School of Public Health, University of Illinois Medical Center, Chicago.

Other scientists who maintain that saccharin is still a cancer risk include Emmanuel Farber, M.D.,
Ph.D., professor of pathology at Jefferson Medical College and chairman of the National
Academy of Sciences' 1978 panel that concluded that saccharin is a carcinogen; William Lijinsky,
former director of the Chemical Carcinogenesis Program at the National Cancer Institute's
Frederick Cancer Research Center; and cancer epidemiologist Devra Davis, director of the
Health, Environment, and Development Program at the World Resources Institute.

The Center for Science in the Public Interest (CSPI), a non-profit health-advocacy organization is
spearheading the opposition to saccharin.

In their letter to the NTP, the scientists described several studies in rats and mice that found that
saccharin caused cancer in the uterus, skin, and several other organs, as well as in the urinary
bladder. Other studies showed that saccharin increased the potency of known carcinogens, such
as methylnitrosourea. In addition, they cited six studies of humans, including a large National
Cancer Institute study, that found an association between artificial-sweetener consumption (the
studies could not distinguish between saccharin and cyclamate) and bladder cancer, especially in
heavy consumers of diet foods.

The scientists acknowledge that saccharin has not been proven to cause cancer in humans, but
they say the studies indicating a risk make it imperative that we consider saccharin dangerous.

Studies published as early as 1957 found that saccharin caused cancer in laboratory animals. In
1977, after a Canadian study proved that high doses of saccharin caused cancer in mice, both the
United States and Canada restricted saccharin use. However, in the U.S., protests by industry and
consumers persuaded Congress to pass a law allowing the unfettered use of saccharin. The law
requires labels of foods containing saccharin to bear a prominent notice advising consumers that
saccharin has caused cancer in laboratory animals.

For the past 20 years, the food industry has sought to eliminate that cancer label. Industry
acknowledges that saccharin causes bladder cancer in rats, but says its research shows that those
cancers result from physiologic changes that only occur when rats ingest large doses of saccharin
and are not relevant to humans.

However, the protesting scientists told the NTP that industry's argument concerning bladder
cancer in male rats is seriously flawed. Moreover, they said industry has failed to explain bladder
tumors in female rats, as well as other kinds of tumors found in some rodent studies and the
human studies indicating an increased risk of bladder cancer.

Michael F. Jacobson, Ph.D., executive director of CSPI, said, "The food industry's arguments are
as artificial as saccharin itself. The cancer label still fits saccharin and consumers should still avoid
it."

According to the National Cancer Institute, the incidence of bladder cancer rose more than ten
percent between 1973 and 1994.

Additional co-signers of the letter to the NTP include Melvin Reuber, M.D., former staff
pathologist, National Cancer Institute and chief of the pathology laboratory in the Chemical
Carcinogenesis Program at the Frederick Cancer Research Center, Erik Millstone, D.Sc., senior
lecturer, Science Policy Research Unit, University of Sussex, England, and author of Additives: A
Guide for Everyone (Penguin, 1988).

CSPI, a health-advocacy organization based in Washington, D.C., is known for exposing
problems caused by sulfite and nitrite preservatives and for opposing the fake fat olestra. It also
campaigned successfully for mandatory nutrition labeling for packaged foods. CSPI is funded
largely by the one million subscribers to its Nutrition Action Healthletter.